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OCR for page 207
Body Composition and Physical Performance 1992.
Pp. 207-220. Washington, D.C.
National Academy Press
Sex Differences and Ethnic/Racial
Differences in Body Size and
Body Composition
Stanley M. Garn
SEX DIFFERENCES IN BODY SIZE
AND BODY COMPOSITION
At all ages, from the first trimester through the tenth decade, the man is
the larger of the two chromosomal sexes, being longer and heavier and with
a larger lean body weight (LBW). Even during childhood, when boys and
girls are most alike dimensionally, the chromosomal XY is considerably
larger than the chromosomal XX of the same physiologic (or skeletal) age.
Because there is some increase in stature even after age 20 and some gain in
the LBW through the midtwenties, the full expression of sex differences in
dimensions and LBW is not evident until late. There are also sex differenc-
es in fat weight (FW), although the woman is not necessarily fatter, either
in absolute terms (FW) or even as a percentage of body weight (percent fat
[% F]), as so commonly believed.
In adulthood, the man is generally taller, by about 6 or 7 percent across
the socioeconomic (SES) range and in different genetic populations. This
stature excess is disproportionately expressed in the appendicular skeleton, a
factor of considerable importance to vehicular design and to the design and
operation of equipment and firearms and the location of controls. In adult-
hood, the man generally has a larger LBW by a ratio of approximately 3:2 (for
example, 61 kg or so versus 43 kg or so). This sex difference in LBW is
reflected in the sex difference in basal energy requirements, in the caloric
207
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208
Stature
STANLEY M. GARN
TABLE 13-1 Distributions of Stature, Weight, Fat Weight, and Lean
Body Weight in 30- to-39-year-old Tecumseh, Michigan Men and Women
Lean Body Weighty
Percent
Weight
Percent
Fat Weight*
Percent
Percent
cm Men Women kg Men Women kg Men Women kgMen Women
140 .0 .0 43 .0 4.1 4 .4.4 20 .0 .0
142 .0 .0 48 .4 13.5 6 3.14.1 25 .0 2.0
144 .0 .0 53 .8 14.3 8 4.25.3 30- .4 10.2
146 .0 .0 58 5.8 23.3 1 0 6.27.7 35 4 25.3
148 .0 .8 63 10.0 17.1 12 7.310.6 40 3.1 30.2
150 .0 1.2 68 15.4 10.2 14 7.38.5 45 14.2 20.0
152 .0 4.1 73 16.5 6.5 1 6 7.37.3 50 21.9 9.8
154 .0 7.3 78 18.5 4.5 18 9.69.3 55 28.1 .8
156 .0 8.2 83 16.2 3.3 20 8.57.3 60 23.1 1.2
158 .4 7.3 88 6.2 .4 22 9.26.9 65 6.5 .0
160 .8 13.5 93 6.2 .8 24 8.14.9 70 1.5 .0
162 1.9 16.3 98 1.5 .0 26 3.82.8 75 .8 .0
164 1.9 9.8 103 1.5 .4 28 5.06.5 80 .0 .4
166 3.5 12.2 108 1.2 1.6 30 6.94.5 85 .0 .0
168 6.5 6.5 1 13 .0 .0 32 4.63.3
170 10.4 6.1 34 5.02.8
172 1 1.9 3.3 36 1.5.8
1 74 1 3.5 1.2 3 8 1.52.0
1 76 1 5.0 1.6 40 .01.2
178 1 1.5 .4 42 .4.0
1 80 5.0 .0 44 .01.6
1 82 8.5 .0 46 .0.4
184 2.7 .0 48 .0.4
186 2.7 .0 50 .0.8
188 1.9 .0 52 .0.4
190 1.9 .0 54 .0.0
192 .0 .0 56 .0.0
194 .0 .0 58 .0.0
*Individually calculated from the regression of weight on four skinfolds.
tTotal body weight (TBW) minus fat weight (FW).
allowances set by the Food and Nutrition Board's (FNB) Committee on Di-
etary Allowances (the Recommended Dietary Allowances the RDAs) and
in caloric intakes actually reported in major nutritional surveys (Ten-State,
NHANES I and II, the Tecumseh Community Health Survey, and so on).
There is, of course, an overlap between the two sexes) in body size,
LOW, FW, and also in skeletal weight (which will be discussed later). For
.
· · 1 ·
.
t For the discussions that follow, also see Figures 13-1 through 13-9 in the chapter appendix,
which graphically present the sexual overlap for body and skeletal weight and size variables in
men and women aged 40-49 years from the Tecumseh Community Health Survey.
OCR for page 209
SEX, ETHNlCl7~Y AND BODY SIZEICOMPOSITION
TABLE 13-2 Distributions of Bone Area, Cortical Area, and Skeletal
Weight in 30-to-39-year-old Tecumseh, Michigan Men and Women
209
Bone Area (TA) Cortical Area (CA) Medullary Area (MA) Skeletal Weight (SW)*
Percent
Percent
Percent
mm Men Women mm Men Women mm Men Women g
Percent
Men Women
35 .0 4.1 20 .0 .4 0 .0 5.3 1400 .0 .8
40 .0 12.8 25 .0 .0 1 2.8 7.8 1900 .0 9.1
45 1.2 24.8 30 .0 1.2 2 3.6 11.9 2400 .8 42.3
50 4.4 22.3 35 .0 11.5 3 4.4 12.3 2900 7.6 32.8
55 4.8 21.1 40 .4 28.0 4 5.2 11.1 3400 16.7 11.2
60 7.6 6.2 45 4.8 30.5 5 6.0 13.2 3900 29.1 3.3
65 16.4 6.6 50 8.8 16.9 6 5.6 10.3 4400 22.3 .4
70 20.0 2.1 55 17.9 7.8 7 11.6 10.7 4900 15.5 .0
75 15.2 .0 60 23.9 2.5 8 6.8 3.3 5400 7.2 .0
80 13.2 .0 65 20.7 1.2 9 5.6 2.9 5900 .8 .0
85 6.8 .0 70 13.1 .0 10 5.2 2.1 6400 .0 .0
90 4.8 .0 75 6.4 .0 11 6.4 2.1
95 3.6 .0 80 2.4 .0 12 7.2 1.6
100 2.0 .0 85 1.6 .0 13 6.4 2.9
14 4.8 .8
15 4.0 1.2
16 1.2 .4
17 2.0 .0
18 4.8 .0
19 .4 .0
20 1.6 .0
21 .8 .0
22 2.0 .0
23 .4 .0
24 .4 .0
25 .4 .0
*SW = 0.969 CA x L or 0.7611 (T2 _ M2)L, where: SW = skeletal weight; CA = cortical
area; L = bone length; T = total width; and M = medullary width.
weight and FW, the overlap is considerable (see Tables 13-1 and 13-21; the
overlap area is of importance to military planning and materiel tariffs from
several points of view. Moreover the actual or operational overlap may be
greater or less depending on recruitment standards, self-selection of volun-
teers, and selective dropout rates. If women who volunteer for service are
self-selected for greater stature or for a larger LOW, as is likely, or if
training programs and the service academies further select, then the women
in service will exceed their total-population (civilian) counterparts in body
size and robust build. At the same time, entry standards, self-selection, and
attrition during basic training may also exclude the smaller and less-mus
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210
STANLEY M. GARN
cled men, thereby decreasing the dimensional and ponderal overlap between
the sexes.
Furthermore, there is the question (which cannot be properly answered
here) as to how much basic training and in-service physical training may
modify, decrease, or even increase sex differences in muscle mass of male
and female volunteers. Both sexes do gain in muscle mass during such
training. There is a common belief that men, with their testosterone, gain
disproportionately more muscle with training, but with joint-sex exercise
programs and suitable motivation, women may gain as much LOW propor-
tionately although they may be liable to exercise-induced amenorrhea due
to decreased estrogenic levels.
Skeletal weight, bone sizes, and amounts of tissue bone all differ be-
tween the sexes even more than LBW differs. So, the calcium content of
the male skeleton approximates 1,000 g as compared with perhaps 750 g for
the female skeleton, and the skeletal weight ratio is then on the order of 4:3.
Moreover the "overlap" in skeletal size or skeletal weight may be well
under 30 percent (see Table 13-2~. With smaller skeletons, less tissue bone,
smaller bone widths, and smaller cortical bone area (CA) one might expect
bone fracture rates to be higher in women than in men, an expectation of
potential importance to the military both with respect to training injuries
and to vehicular accidents. However in actual experience, civilian fracture
rates are higher for men than for women in the age range of 20 to 40 years.
Only after the fifth decade does the fracture rate in women begin to exceed
the fracture rate in men.
Why men under 45 years of age fracture more and women aged 20 to
45 fracture less is not known, although men are more often engaged in high-
risk construction occupations, and they are more accident-prone when they
drive (and they do drive more miles). However, the smaller bones of young
adult women do not necessarily result in a higher fracture rate in civilian
life. Again, the overlap in bone size and bone area between men and
women must be considered as shown in Table 13-2. What the actual os
seous overlap is in enlisted men and women and those at noncommissioned
officer and officer ranks remains to be ascertained. Also to be ascertained
is the incidence of forearm (Colles' and Parry) fractures in military-age
individuals of both sexes.
The question of sex differences in fat weight (FW) and percent fat (%F)
is complicated, and some of the answers are surprising. That women gener-
ally do have a thicker panniculus of outer fat is well known, but this is not
always the case; some women have less outer fat than men do. When FW is
measured, the two sexes are often quite similar, a fact that is not well
appreciated (Table 13-31. Yet percent fat (%F) is generally higher in wom-
en because FW may be the same, but total body weight (TBW) is consider-
ably less. Even so, the overlap in percent BF is considerable.
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SEX, ETHNICITY AND BODY SIZEICOMPOSITION
TABLE 13-3 Correspondences Between Male and
Female Percentiles for Size and Body Composition in
30-to-39-year-old Tecumseh, Michigan Men and Women
Male Centiles Corresponding to
Women's Fiftieth Women's Eighty-fifth
Measure Percentile Percentile
Stature
Weight
Fat weight
Lean body weight
Bone area (TA)
Cortical area (CA)
2.0
7.0
45.0
2.3
3.4
2.0
Medullary area (MA) 34.4
Skeletal weight (SW) 0.8
13.1
40.6
88.5
18.1
10.4
14.0
48.0
8.4
NOTE: This table is to be read in the following manner. The fiftieth
percentile for stature in women corresponds to the second percentile in
men. The eighty-fifth percentile for stature in women corresponds to the
thirteenth percentile for men. Note that the sexes are most alike in fat
weight and skeletal weight.
211
As a complication, fatness either fat thickness or FW is inversely
related to education in women at a rate of nearly -O.S kg per year of educa-
tion, which suggests that how fat a woman is depends largely on her socio-
economic status. If the military recruits only women of high school educa-
tion (12 years) or beyond, their fatness may be lower than the average, and
even lower than that for men of similar educational level. Moreover, leaner
women may self-select for military service, and fatter women may be ex-
cluded from advancement or continuation in the service. The point here is
that the appropriate level of fatness for service-oriented women cannot be
prejudged from total-population or national-probability FW distributions.
A further point about fatness is derived from family-line studies. There
are large familial differences in fatness levels. Daughters of lean families
are far leaner than sons of obese families. This finding again opens the
question as to whether women are necessarily or inherently fatter than men
even though on the average they are.
In the civilian population, fat weight (FW) increases regularly and lin-
early with age at a rate of approximately 0.5 kg/year in women. However,
this age-related increase is not necessarily a biological "given," occurring
far less in the affluent and somewhat more in the poor. So an age-related
increase in fatness is not necessarily the universal rule. Indeed in some
third world countries fatness actually decreases with age. With one excep
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212
STANLEY M. GARN
lion, one might even consider a no-increase rule for FW in the military as
being both desirable and practical. The exception has to do with pregnancy,
where higher levels of fatness are advantageous for fetal growth and devel-
opment (see below, "Relevant Epidemiologic Aspects of Fatness and Fit-
ness"~.
ETHNIC AND RACIAL DIFFERENCES IN BODY MASS
AND BODY COMPOSITION
Although many ethnic and racial differences in size and body composi-
tion have been claimed and some documented, it is quite difficult to sepa-
rate most such differences from years of residence in the United States and
from socioeconomic status (SES). Male and female immigrants of recent
arrival tend to be smaller, poorer, and shorter, but the immigrant women
soon become fatter and more often obese. However, both size and body
composition change as ratios of income to needs improve. Such differences
between immigrants and their Fit progeny pose problems in setting military
standards exactly the same problems that were encountered by the first
Committee on Military Anthropometry in 1917. That wartime committee
recommended a lowering of stature and weight standards so that recent
immigrants from Russia and the Austro-Hungarian Empire would not be
subjected to the height and weight standards established for so-called "na-
tive Americans".
In recent years there has been much litigation concerning weight and
weight-height standards for airline stewardesses, oil industry workers, post-
al workers, and even Sears Roebuck shipping clerks. Courts have ruled that
military, National Center for Health Statistics (NCHS), and the Metropoli-
tan Life Table standards for size or weight-for-height are not necessarily
appropriate for Mexican-Americans, Puerto Ricans, Colombians, and oth-
ers. Even people with extremes of weight-for-height have been ruled as
employable as long as those individuals can do their jobs, such as lifting
80-pound mail sacks.
Most immigrants from Meso-America, South America, the West Indies,
and the Philippines and Asia are shorter than the NCHS norms and conse-
quently have a smaller lean body weight (LBW). Such individuals and their
foreign-born children are small by American military standards and may be
accorded restricted military duties or excluded from certain classes of troops.
With increased length of stay in the United States, and now in the F2
generation, these immigrants more nearly parallel other Americans.
American Blacks (Americans of largely African ancestry) pose an in-
triguing problem, for they are taller as children and adolescents (ages 2
through 14) than are Whites of comparable age. As adults they average
close to the U.S. means, may be taller than other Americans of comparable
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SEX, ETtINICI7~Y AND BODY SIZEICOMPOSITION
213
socioeconomic status, and with an excess above the ninety-fifth percentile
limits. American Blacks (or African-Americans) also appear to have a
slightly higher LBW, which indicates a larger muscle mass.
Best documented and of considerable interest is the larger bone mass in
African-Americans. This difference is apparent in the fetal condition, dur-
ing infancy and childhood, and continuing through the tenth decade of life.
This larger skeletal mass (larger bone diameters and larger volumes of cor-
tical bone) may be one factor behind the lower fracture rates for adult
Blacks of both sexes. However the larger skeletal masses (bone weights
and tissue bone volumes) may not be translatable into duty assignments.
Much attention has been given in the literature to the greater fatness of
Black women, Hispanic women, Native American women, and so on. In-
deed, fatness and obesity in Native American women have been attributed
to population-specific "thrifty" genes. However this greater fatness appears
to be more of a poverty-related phenomenon than a true genetic difference.
Poor White women are fatter than affluent White women, and fatness de-
creases linearly with both years of education and family income. Fat weight
(FW) also decreases with increasing socioeconomic status in Black women.
There may be good political reasons to accept higher-weight and fatter
Black, Meso-American, and Native American women into military service,
but there can be no assumption that such differences are necessarily genetic.
Studies have also claimed racial and ethnic differences in fat place-
ment, fat distribution, or fat "patterning". Expressed as ratios (for example,
triceps:subscapular), such differences do exist, but these ratios are inherent-
ly fatness dependent. The triceps:abdominal circumferential ratio is much
higher in lean individuals and much lower in the obese, so that some racial
differences in fat placement may be no more than simple differences in the
amount of fat. Of course, clothing and other covering equipment may be
affected by such differences, but differences in relative leg length or hand
size or foot size relative to stature may be more important. For constant
stature, hand lengths and foot lengths (or metacarpal lengths and tarsal
lengths) are approximately 1 standard deviation (SD) longer in American
Blacks, whatever their nutritional status.
There are real and considerable ethnic and racial differences in body
size and body composition, and in an emergency or crisis situation they
may be taken into account. However, many of these differences (except the
greater LBW and bone weight in African-Americans) disappear with time,
affluence, and generational changes. The greater fatness of low-income
women of all ancestries is very real and bears on recruitment and enlistment
standards, but it is not necessarily genetic. How such differences are ad-
dressed involves political decisions, which may be discriminatory, however
decided. It is probably beyond the scope of this advisory group to attempt
ethnic-specific recommendations.
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214
STANLEY M. GARN
RELEVANT EPIDEMIOLOGIC ASPECTS
OF FATNESS AND FITNESS
The weight of fat (FW) and therefore the percent of fat (OF) is control-
lable both by caloric restriction and by increasing energy expenditure. This
fact is important both with respect to field performance and to long-term
mortality and morbidity. Controlling FW or percent F affects field perfor-
mance over the short term and affects the development of atherosclerosis,
coronary artery disease, diabetes, and hypertension later on.
However, existing recommendations regarding the ideal, suggested, or
optimal weight of fat are complicated by the nonlinear relationship between
FW and age-specific mortality. At the upper end of the J-shaped curve,
both morbidity and mortality rise with increasing levels of fatness. In
contrast, morbidity and mortality also increase at the bottom end of the
curve, where diseases of the respiratory system, including lung cancer, pre-
dominate. Very lean individuals of either sex are clinically anorectic and at
greater long-term risk.
risk.
Very fat individuals are also at greater long-term
Low fat weights in women are of concern if they are associated with
amenorrhea, and premature bone loss is likely for this group. Women
athletes may find such low fat levels advantageous in the short term be-
cause it frees them from the inconveniences of menstruation. However, the
premature onset of bone loss and involutional osteoporosis in these women
might then be claimed as a service-related disability.
Furthermore, the ideal level of fatness associated with ideal fitness in
women is far less than the level of fatness associated with optimal fetal
growth and survival. Too lean a mother may be at greater risk for fetal loss,
premature delivery, low birth weight, and increased neonatal mortality. Because
a low prepregnancy weight (PPW) can be compensated for by a greater
pregnancy weight gain, this aspect of body composition also merits atten-
tion in military service.
The long-term consequences of differences in FW also merit consider-
ation. Because the Veterans Administration bears the cost of diseases asso-
ciated with excessive fatness, body composition long after separation from
service may well be an extended task of this conference. Pregnancy and
pregnancy-associated risks are not necessarily part of the assigned mission,
but body composition is important during pregnancy; too little fat is a risk
factor with respect to pregnancy outcomes, and insufficient weight or fat
may be a life-long risk-factor.
Concerns of the military in the past were relatively short-term, relating
to the ability of draftees and recruits to perform assigned tasks after entry
into the services. Body size and bodily proportions also had some bearing
on the design of equipment and on the number of sizes to be stocked.
OCR for page 215
SEX, ETHNICITY AND BODY SIZEICOMPOSITION
215
Concerns now include changes in body composition during extended peri-
ods of service up to 2 decades and more and fatness control to meet
service standards. Moreover, there are the long-term implications both to
service-induced disabilities and to the cost of medical care long after sepa-
ration from the services. If the services are to be equal-opportunity em-
ployers, they must accommodate racial and ethnic differences in size and
body composition, including Vietnamese and Hispanics from southern Tex-
as, California, and Florida. Looking to the future, there are the costs of
hospitalization and medical care for those with excessive fatness and claims
for service-induced disabilities. Even the children of those now in the
service may seek compensation for excessive physical demands on their
parents or for their own premature birth if their mothers were allowed to be
too lean when they were in utero.
ACKNOWLEDGMENTS
All tabulations for age 30-39 year old men and women were specially
calculated for this paper by Timothy V. E. Sullivan using raw data from the
Tecumseh, Michigan Community Health Survey, including radiogrammetic
measurements made under contract 53-3K06-5-10 with the Human Nutri-
tion Research Center on Aging. Graphic representations for the 40-49 year
old age group in Figures 13-1 through 13-9 in the chapter appendix use
superimposed transparencies made from computer-generated histograms for
men and women separately.
APPENDIX
The following figures were generated from superimposed transparen-
cies made separately for men and women from computer-generated histo-
grams. Data from the Tecumseh, Michigan Community Health Survey for
individuals aged 40-49 were used throughout and thus provide comparative
information for sexual overlap with the data from the same population on
individuals aged 30-39 presented in Tables 13-1 through 13-3.
OCR for page 216
216
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FAT WEIGHT
MALE~40-49)-X
FEMALE~4~49)-O
FIGURE 13-1 Distribution of fat weight (FW) in kilograms (kg) in fifth decade
(40-49 y) men (O) and women (X), where each X or 0 = 1 person. Note the
completely overlapping distributions of FW in fifth decade men and women. A1-
though percent body fat does differ markedly between the sexes, because of the
larger body weight in men, the distribution of fat weight is similar.
43 000 +~8
48.000 +0000000000000
53.000 +800000000000000000000000
58.000 +~0000000000000000000000000
63.000 +~.ab6~OOOOOOOOOO
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98.000 ~XXXXXX
103.00
108.00
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MALE~40-49)-X
FEMALE~40-49)-O
FIGURE 13-2 Distribution of body weight in kilograms (kg) for fifth decade (40-
49 y) men (O) and women (X), where each X or 0 = 1 person. Note the overlapping
distributions of weight in men and women. Because the fat-free weight of men is
considerably larger than that of women, there is some bimodality in the body weight
distribution, and this is especially apparent at the higher income levels.
OCR for page 217
OCR for page 218
OCR for page 219
OCR for page 220
Representative terms from entire chapter:
body composition
217
AX
+o
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2 5 . 000
30 000
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4 5 . 000
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7 5 . 000
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218
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FIGURE l 3-5 Distribution of
height in centimeters (cm) for
fifth decade (40-49 y) men (X)
and women (O), where each X
or 0 = l person. Although the
percentage difference in stat-
ure is small only 7 percent or
so- male and female statures
show very little distributional
overlap, a fact that has consid-
erable bearing on equipment
design, materiel tariffs, and pur-
chasing schedules.
O . ~ 000
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FIGURE 13-6 Distribution of ~ ~ 000 + xxxxxx
medullary cavity area in mini- ~ ~ 000 ~ x x x x
meters (mm) for fifth decade (40- ~ ~ . Too +.x x x
49 y) men (X) and women (Oy, 16 000 +6x x
where each X or 0 = 1 person. ~ 7 000 ox
· 1 ~ . ~ X X x MEDULLARY AREA
Note that there is considerable 18 000 ax MALE~4~49)-X
overlap between the sexes in med- :20 . 000 ~ Y x FEMALE~4~49)-O
ullary cavity area, although the 2 ~ .000 fix
men, with greater hematopoiet- 22 000
· 2 3 . Coo
1C capacity, do have larger 2 ~ OoO
amounts of red marrow. 25 .000
219
20.000
2S . 000
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IS . 000
40.~
US COO
50 . 000
55 000
CO . 000
C5 000
70 000
7 S 000
e0 . 000
BS .
+00000
+0000000~000~000000000
+00000~0000000000000000-0000000000000
+~80~040000000000000000000000000000000
+~-00000
+~ -XYXXXXXXXXXXXXX
+~0XXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXX
~XXXXXXXXXXXX
+8XXXXXX>`XXX8~.IXX
+yXXxxx
XX
CORTICAL AREA
MALE~40-49)-X
FEMALE~40-49)0
FIGURE 13-7 Distribution of cortical area in millimeters (mm) for fifth decade
(40-49 y) men (X) and women (O), where each X or 0 = 1 person. Note that there
is considerable sexual dimorphism in the cortical area. The overlap is small less
than 15 percent because men have far more tissue bone.
3 5 000
40. 000
~ 5 .
50 . 000
5 5 . 000
60 . 000
6 5 . 000
70 . 000
7 5 . 000
80.~
8 5 . 000
so . ooo
9 5 . ooo
1 00 . 00
+0000000
+000000000000000000000000~0
+~000000000000000000000000~0000
+~00000~00000000000000000000000000000000
+~ 000000000000
-XXXXX
+ _ XXXXXXXXXXX
+- XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
"XXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
XXXXXXXXX
XXXXXXXXXXX TOTAL AREA
X X X X MALE~4~49)-X
FEMALE~4~49)-0
FlOURE 13-S Distribution of total bone area in millimeters (mm) in fifth decade
(40-49 y) men (X) and women (O), where each X or 0 = 1 person. Note that when
total bone area is taken into account there is even further sexual dimorphism than
for cortical area alone. The male skeleton possesses greater impact resistance than
the female skeleton. This is especially true in the forearm where relatively light
trauma such as falling-can result in a Colles or Parry fracture.
220
S~FLETAl WEIGHT
S4(~()() +0000 BRALESS
Sl()().() +0OOOcOOOOOOOOOOO FE-ALES-o
49()().() ~ooooooooooooooooooooo
4('()()() +600000000000000 ~ 0000000000000~ 000000
4-~(~(~() +0000000000000000000000000000000000
4(~()(~.() +~800000
37(~.() HEX
34~)~}(} +~8XXXXXXXXXXXXXX'XX
`31()~).~} ~XXXXXXXXXXXXxXXXXXXXXX
2X()(~.(} +aXXXXXXXXXXXXXXXXXX
25~)~).() ~XXXXXXXXXXXXXXXXXXXX
22~)~).~) ~XXXXXXXXXXX,
19()().(' ~XXXXXXXXXX
1 6(~(~.() +.X
1 3(~(~.() ~ X X
1 ()()().() ~ X X
FIGURE 13-9 Distribution of skeletal weight in grams (g) for fifth decade (40-49
y) men (X) and women (0), where each X or 0 = 1 person. Note that the skeletal
weight distributions in men and women are most different with very little overlap.
Skeletal weight thus sums, in effect, the distributional properties of stature and the
fat-free weight. The sex difference in skeletal weight plays an important role in
human identification in mass disasters and skeletal weight alone affords close to 90
percent sex discrimination.
